Conventionally, scanners are used, for example, in scanning devices included in optical devices such as electrophotographic copiers, laser beam printers, and barcode readers, and scanner apparatuses included in tracking control devices for optical disks. The scanners are used in image display devices that display two-dimensional images by defecting and two-dimensionally scanning light.
The scanners have a mirror to which a laser beam is emitted, and oscillate the mirror in such a way that the laser beam reflected off the mirror is scanned on the top surface of a screen or the like. In the case of two-dimensionally scanning a laser beam, it is common to adopt two-axis scanning or separate scanning using scanners for horizontal motion and vertical motion. Specifically, a system for scanning along two axes with one scanner and a system for two-dimensional scanning through one-dimensional scanning processes with two scanners combined in the orthogonal directions have been proposed.
In recent years, a scanner with a micro mirror has been proposed which is manufactured using the semiconductor process technology and the micro electronic mechanical system (MEMS) technology (for example, refer to Patent Literature (PTL) 1). Especially, a scanner manufactured using the MEMS technology (an MEMS scanner) can be reduced in size and is capable of high speed operation as advantageous effects, and therefore is expected to be used in a high-resolution laser display and the like.
When the MEMS scanner is used in a display, two-dimensional deflection through raster scanning is adopted. The raster scanning is a combination of high-speed horizontal scanning (in the order of a few tens of kilohertz) and low-speed vertical scanning (in the order of a few tens of hertz). In the MEMS scanner, the high-speed horizontal scanning is performed by sine wave drive using a resonant frequency and the low-speed vertical scanning is performed by non-resonance drive using ramp waves so that the resolution can be increased.